CHAIN BAR FOR A POWER CHAIN SAW

摘要

AN IMPROVED CHAIN SAW BAR FOR A POWER CHAIN SAW by William Cumming Leith, a Canadian citizen whose postal address is P.O. Box 157, Trail, B.C. Canada V1R4L4 An improved chain bar for a power chain saw consists of a replaceable chain bar with at least one thru-slot with a machined slot edge profile. The thru-slot is filled with a damping insert with matching insert edge profile and made of at least one damping material which retains the maximum energy efficiency for wood sawing, but damps out up to 95 % of the combined longitudinal tension/compression and transverse/ lateral bending resonant vibrations going to the hand grips, and hence to the operator's fingers. The size of a thru-slot expressed as its diameter is one quarter to one half of the width of the chain bar. The number of thru-slots with insert is generally in the range of one to ten. The thru-slots are located on the longitudinal axis of the chain bar between the point of mounting and the guide sprocket, and at locations of the maximum deflection for the harmonics of the vibrations in the chain bar.